A pair of standard 20° spur gears with 10-in. center distance has a velocity ratio of 4.0. The pinion has 20 teeth.
(a) Determine P, p, and Pb.
(b) Begin a full-size layout showing partial pitch circles, partial base circles, pressure angle, addendum, and dedendum. Label each of these on your drawing.
(c) Show on your drawing the interference-limiting maximum addendum radii, rag,max, and rap,max. Scale their numerical values from the drawing. Will interference be encountered with teeth of standard proportions?
(d) Measure on the drawing the length of the path of contact for standard tooth proportions and, from this, compute the contact ratio.